WEE1 kinase regulates CDK1 and CDK2 activity to facilitate DNA replication during S-phase and to prevent unscheduled entry into mitosis. WEE1 inhibitors synergize with DNA-damaging agents that arrest cells in S-phase by triggering direct mitotic entry without completing DNA synthesis, resulting in catastrophic chromosome fragmentation and apoptosis. Here, we investigated how WEE1 inhibition could be best exploited for cancer therapy by performing a functional genetic screen to identify novel determinants of sensitivity to WEE1 inhibition. Inhibition of kinases that regulate CDK activity, CHK1 and MYT1, synergized with WEE1 inhibition through both increased replication stress and forced mitotic entry of S-phase cells. Loss of multiple components of the Fanconi anemia (FA) and homologous recombination (HR) pathways, in particular DNA helicases, sensitized to WEE1 inhibition. Silencing of FA/HR genes resulted in excessive replication stress and nucleotide depletion following WEE1 inhibition, which ultimately led to increased unscheduled mitotic entry. Our results suggest that cancers with defects in FA and HR pathways may be targeted by WEE1 inhibition, providing a basis for a novel synthetic lethal strategy for cancers harboring FA/HR defects.

Therapeutic drug monitoring (TDM) with measurement of serum drug and antidrug antibodies (ADAb) is used widely to confirm therapeutic exposure, rule out immunogenicity, and optimize treatment of biologics in patients with inflammatory bowel diseases.¹ A recent genome-wide association study found the variant HLA-DQA1∗05 to increase the risk of development of antibodies against infliximab (IFX) and adalimumab (ADM) 2-fold, regardless of concomitant immunomodulator use.^2,3 However, there is currently limited evidence showing whether patients who develop antibodies to 1 anti-tumor necrosis factor (TNF) are prone to develop antibodies to the subsequent anti-TNF. Our aim was to investigate the risk of subsequent antibody development in cases (with ADAb to prior anti-TNF) versus control subjects (without ADAb to prior anti-TNF) using a large cohort of patients with inflammatory bowel diseases who underwent TDM with a drug-tolerant assay.

Background and aims

Few studies evaluate the impact of anesthesia providers during procedures, such as colonoscopy, on low-risk patients. The objective of this study was to compare the effect of anesthesia providers on several outcome variables, including major morbidity, following screening colonoscopies.

Methods

A propensity-matched cohort study of 14,006 patients who enrolled with a national insurer offering health maintenance organization (HMO), preferred provider organization (PPO), and Medicare Advantage plans for a screening colonoscopy between July 1, 2005 and June 30, 2007 were studied. Records were evaluated for completion of the colonoscopy, new cancer diagnosis (colon, anal, rectal) within 6 months of the colonoscopy, new primary diagnosis of myocardial infarction (MI), new primary diagnosis of stroke, hospital admission within 7 days of the colonoscopy, and adherence to guidelines for use of anesthesia providers.

Results

The presence of an anesthesia provider did not affect major morbidity or the percent of completed exams. Overall morbidity within 7 days was very low. When an anesthesia provider was present, a nonsignificant trend toward greater cancer detection within 6 months of the procedure was observed. Adherence to national guidelines regarding the use of anesthesia providers for low-risk patients was poor.

Conclusion

A difference in outcome associated with the presence or absence of an anesthesia provider during screening colonoscopy in terms of MI, stroke, or hospital admission within 7 days of the procedure was not observed. Adherence to published guidelines for the use of anesthesia providers is low. The incidence of completed exams was unaffected by the presence of an anesthesia provider. However, a nonstatistically significant trend toward increased cancer detection requires further study.

Background & aims

Some women with inflammatory bowel disease require therapy with tumor necrosis factor (TNF) antagonists during pregnancy. It is not clear whether these drugs are transferred to the fetus via the placenta and then cleared, or whether structurally different TNF antagonists have different rates of transfer.

Methods

We studied 31 pregnant women with inflammatory bowel disease receiving infliximab (IFX, n = 11), adalimumab (ADA, n = 10), or certolizumab (CZP, n = 10). Serum concentrations of the drugs were measured at birth in the mother, infant, and in cord blood, and then monthly in the infant until the drugs were undetectable. Drug concentrations in the cord and the infant at birth were compared with those of the mother.

Results

Concentrations of IFX and ADA, but not CZP, were higher in infants at birth and their cords than in their mothers. The levels of CZP in infants and their cords were less than 2 μg/mL. The median level of IFX in the cord was 160% that of the mother, the median level of ADA in the cord was 153% that of the mother, and the median level of CZP in the cord was 3.9% that of the mother. IFX and ADA could be detected in the infants for as long as 6 months. No congenital anomalies or serious complications were reported.

Conclusions

The TNF antagonists IFX and ADA are transferred across the placenta and can be detected in infants at birth; the drugs were detected in infants up to 6 months after birth. CZP has the lowest level of placental transfer, based on levels measured in cords and infants at birth, of the drugs tested.

Background & aims

Crohn's disease (CD) has the highest prevalence in Ashkenazi Jewish populations. We sought to identify rare, CD-associated frameshift variants of high functional and statistical effects.

Methods

We performed exome sequencing and array-based genotype analyses of 1477 Ashkenazi Jewish individuals with CD and 2614 Ashkenazi Jewish individuals without CD (controls). To validate our findings, we performed genotype analyses of an additional 1515 CD cases and 7052 controls for frameshift mutations in the colony-stimulating factor 2-receptor β common subunit gene (CSF2RB). Intestinal tissues and blood samples were collected from patients with CD; lamina propria leukocytes were isolated and expression of CSF2RB and granulocyte-macrophage colony-stimulating factor-responsive cells were defined by adenomatous polyposis coli (APC) time-of-flight mass cytometry (CyTOF analysis). Variants of CSF2RB were transfected into HEK293 cells and the expression and functions of gene products were compared.

Results

In the discovery cohort, we associated CD with a frameshift mutation in CSF2RB (P = 8.52 × 10(-4)); the finding was validated in the replication cohort (combined P = 3.42 × 10(-6)). Incubation of intestinal lamina propria leukocytes with granulocyte-macrophage colony-stimulating factor resulted in high levels of phosphorylation of signal transducer and activator of transcription (STAT5) and lesser increases in phosphorylation of extracellular signal-regulated kinase and AK straining transforming (AKT). Cells co-transfected with full-length and mutant forms of CSF2RB had reduced pSTAT5 after stimulation with granulocyte-macrophage colony-stimulating factor, compared with cells transfected with control CSF2RB, indicating a dominant-negative effect of the mutant gene. Monocytes from patients with CD who were heterozygous for the frameshift mutation (6% of CD cases analyzed) had reduced responses to granulocyte-macrophage colony-stimulating factor and markedly decreased activity of aldehyde dehydrogenase; activity of this enzyme has been associated with immune tolerance.

Conclusions

In a genetic analysis of Ashkenazi Jewish individuals, we associated CD with a frameshift mutation in CSF2RB. Intestinal monocytes from carriers of this mutation had reduced responses to granulocyte-macrophage colony-stimulating factor, providing an additional mechanism for alterations to the innate immune response in individuals with CD.